1. Field of the Invention
This invention relates to the precision machining of workpieces and to a form of vise for use therein.
2. Description of the Prior Art
Those skilled in the art are aware of the vise shown in U.S. Pat. No. 4,529,183, which is a precision vise having means for holding workpieces in each of two positions with respect to a central fixed jaw. The problems which can be solved when a central fixed jaw is in position are adequately explained in the above-mentioned patent.
In the structure shown in U.S. Pat. No. 4,529,183, the central fixed jaw member is shown as being bolted from the bottom, rather than from the top, and the equipment also lacks a detachable means attached to the handle end of the device which is capable of securing the movable jaw proximal to the handle in a predetermined position.
It has been evident to those skilled in the art that the structure shown in U.S. Pat. No. 4,529.183, while it is very advantageously useful for the handling of the precision machining of workpieces that need to be worked upon while they are in two different orientations, nevertheless is not especially suitable for jobs which occasionally arise and involve the grasping of a workpiece through a relatively large grasped dimension. In the commercially available version of the vise shown in the above-mentioned patent, the greatest grasped dimension is on the order 3 or 4 inches, and it is frequently desirable to be able to work with workpieces where the grasped dimension is considerably greater, being on the order of 10 or 12 inches. At the same time, it is desirable for the equipment to be such that it may readily be converted to a two-place vise and operated in the particular manner described in the above-mentioned patent.
The applicant has had a considerable measure of commercial success with the marketing of a device which, accordingly, represents a modification of the equipment shown in the above-mentioned patent, such that the central jaw member is bolted from above, so that it is readily accessible for removal, and detachable means are provided near the handle end of the screwshaft for fixing the location of one of the two jaws of the apparatus traversed by the screwshaft operated by the above-mentioned handle.